Drill



A. L. HAWKESWORTH.

DRILL.

APPLICATION FILED MAH. 2l, 1919.

'Patented Mar. 1, 1921. Q

' erro/m5 Y.

UNITED sr,...v

ARTHUR L. HAWKE-SWORTH, OF EUTTE, MONTANA..

DRILL.

Specification of Letters Patent.

Patented Mar. 1, 1921.

Application e. March 21, 1919. Serial No. 283,951.

To all whom it may concern.

Be it known that I, ARTHUR L. Hawkins- WORTH, a citizen of the United States, residing at Butte city, in the county of Silverbow and State oi Montana, have invented certain new and useful improvements in Drills, of which the following is a full, clear, and exact" description, reference being had to the accompanying drawings, forming a part hereof. y

The present invention is directed to iinproveinents in drills, and has for its object to provide a detachable bit or cutting end for a drill bar or shank for the purpose of drilling holes in rocks, in the ground, lor

in any hard substance whatsoever. A yfurther object is to provide means for tastening the bit in such a way as to insure its retention on the bar or shank while in service, and yet permit instant removal of the bit when desired, as for example when it becornes necessary to detach an old bit and attach a new one, or when a bit is removed troni the shank for saiekeeping in a tool chest, or detached for purposes of sharpenin or for any other purpose. A further object is to provide a suitable stop for the bit when it has reached its working position on the shank, and to provide fuit er and other structural features the advantages of which will be fully apparent from the iollowing detailed description in connection with the accompanying drawings in which- Figure l represents an elevation of a drill turned so as to present the wide end of the dove-tail tapering tongue of the shank received by the corresponding groove of the bit or cutter; Fig. 2 is a side elevation' of the drill with parts broken away; Fig. 8 is an elevation of the bit detached from the shank and turned to present the wide end of the groove which receives the terminal ton e'ot the shank; Fig. a is an elevation of t e shank turned to present the wide end ot the tongue received by the groove of the bit; Fig. 5 is a bottom plan of the bit; and Fig. 6 is an end view of the shank showing in plan the terminal tongue thereo'received 'by the groove of the bit.

"Referring to the drawings, 1, represents :a "drill-bar or shank provided with a central or axial passageway or duct a for the ow of water usually employed in drilling o erations as well understood in the art. he shank terminates at one end (the endopposite that from which the same is operated) in a dove-tail tongue 2 the side walls whereottaper 1n the general direction toward the drilling or cutting end of the tool, the tongue being bounded by'ofsets t, t, disposed in. a common transverse plane inclined to the axis of the shank, said plane being parallel to the plane of the top face fz. of the tongue. The offsets t, t, and face la, form the supporting surfaces for the detachable bit 3 provided with a central or aXial passage-way or duct a. which, when the bit is in working position on the shank forms a continuation of the duct a, The bit 3 ,-is formed with a groove d the inner faces of the'bounding or side walls w whereof engage the sides of the tongue, the bottom of the groove conforming in inclination to that of the face z. of the tongue so as to cause the tongue to fit snugly in the groove, the transverse edges o of the side walls of the groove restingon the offsets t. it will be seen from the foregoing that a'pressure on the shank in the line of the axis thereof will tend to drive the drilling end of the shank upward along the inclined plane of the groove bottom, or what amounts to the same thing, tend to force the bit downward along the inclined plane of the face h of the tongue, thereby tending to tighten the bit on the shank during the drilling loperation rather than to loosen it. On the other hand, to detach the bit from the shank all that is necessary is to tap the bit on the side et the large or wide end of the tongue (at the wide end of the groove) thereby forcing the bit across the longitudinal axis of the shank toward the narrow end of the tongue, or in the direction shown by the arrow in Fig. 2, the loi-l;A readily slipping ofi the tongue.

in the present embodiment of my. invention I provide means for arresting or stopping the bit in its movement across the axis of the shank when the bit reaches its operating or working position. This arresting means is preferably in the form of a stoppiece or Iboss 4 formed with or secured to the tongue at the wide end thereof and projecting above the top surface h of' the tongue, said-stop 4 being rounded or U- shaped as shown, and "being received by a similarly shaped recess 1- fornied 'at the corresponding end of the groove d of the bit, said recess being depressed below the plane of the groove bottom as shown, and opening outwardly to receive the stop piece,

being in no Wise a departure from the ge-- -neric idea contemplated by the invention.

The invention is of course applicable to any reciprocating or rotating shank, bar, or other member employed for drilling or boring purposes, to which a bit or cuttlng end may be applied and to which it may be detachably secured.

It will be seen from the foregoing that the coupling means by which the bit is secured to the drill bar or-shank is such as to cause the bit to be locked or tightened to the shank by a relative movement of the parts across the axis of the shank ina given direction, the bit becoming loosened from the shank by a corresponding movement of the parts in the opposite direction. The bit is arrested or stopped to prevent undue binding when once it reaches its operating or Working position.

Having described my invention What I claim is:

l. In combination with a drill-bar or shank terminating at one end in a dove-tail tongue bounded on either side by offsets formed by said end, the side Walls of the tongue tapering in the general direction toward the cutting end of the drill, the faces of the offsets and top face of the tongue beingl parallel and disposed on a diagonal or at an incline to the shank axis, a bit movable across the axis of the shank and provided With an open ended groove to receive the tongue, a stop-piece leading from one end of the formation on one member toward the shank axis and coperating With a recess on the corresponding end of the formation on the opposite member, to arrest the bit When the same has been moved to Working position on the shank.

2. In combination With.` a drillbar or shank terminating at one end in a dove-tail tongue bounded on either side by offsets formed by said end,'the side Walls of the tongue tapering in the general direction to- Ward the cutting endl of the drill, the faces of the offsets and the top face'of the tongue bemgvparallel to one another and disposed on a diagonal or at an incline to the shank axis, a bit movable across the shank provided With a groove open at both ends to receive the tongue, a stop-piece at the Wide end of lthe tongue projecting above the top face of the tongue and coperating With a recess formed on the bit at the adjacent end of the groove.

In testimonfy whereof I aiiix my signature 1n presence o two Witnesses. v

ARTHUR L. HAWKESWORTH. Witnesses:

RAY S. ALLEY, JOHN J RILEY. 

